PORT-AU-PRINCE, Haiti — Tropical Storm Chantal skirted the southern coasts of the Dominican Republic and Haiti on Wednesday, losing force but still posing a flood threat to some of the region’s most vulnerable people.

The storm was no longer expected to make landfall on the island of Hispaniola shared by the two nations and Dominican officials suspended a tropical storm warning for that country. But forecasters said Chantal could still bring heavy rain to flood-prone areas where people live in flimsy homes of plywood and corrugated steel.

In both countries, people fortified houses with tarps and wood and gathered supplies, largely ignoring warnings to leave their neighborhoods.

“We’re going to wait until it’s over. We’re already used to this,” said 36-year-old Sergio Guzman, who lives along the banks of a river near Santo Domingo.

Dominican state meteorologist Bolivar Ledesma said as much as 8 inches of rain could soak that country’s southern coast.

As showers began falling along Haiti’s southern coast Wednesday afternoon, officials took to the radio airwaves to urge people to move away from ravines, secure important records and stock up on food and water.

“There’s not much I can do,” Stevenson Etienne, a 40-year-old welder, said from his garage in downtown Port-au-Prince. “Still, I will try to protect myself and my children.”

Chantal was about 145 miles south of the Haitian capital of Port-au-Prince late Wednesday afternoon, moving west at 29 mph, with maximum sustained winds of 45 mph, according to the U.S. National Hurricane Center in Miami. It was on track to head north across Cuba and toward the Bahamas and Florida, but forecasters said the storm would likely weaken to a tropical depression today.

A tropical storm warning was in effect Wednesday for Haiti, Turks and Caicos and the southeastern Bahamas. A tropical storm watch was in effect for Jamaica and the central Bahamas.

Even a weaker Chantal could create problems for the rural southern peninsula of Haiti and southwestern Dominican Republic.

Storms often trigger flooding and landslides on Hispaniola, and severe deforestation and makeshift housing make Haiti especially vulnerable.

Port-au-Prince is a hilly city on the ocean that’s surrounded by vast concrete shanties that collapse in mudslides, sometimes killing people. Also, about 279,000 Haitians still live in ramshackle settlements established after a devastating 2010 earthquake.

Last year, a hurricane and a tropical storm separately caused widespread flooding after merely brushing Haiti.

Marie Alta Jean-Baptiste, general director for Haiti’s Civil Protection Department, said the government had prepared 400 emergency shelters nationwide. She urged people to tie up livestock, monitor the radio for updates and avoid crossing rivers.

American Airlines canceled flights to Haiti and elsewhere in the Caribbean.

Chantal raced through the eastern Caribbean early Tuesday, with officials in Dominica reporting that heavy winds ripped the roofs off several homes. No injuries were reported there or anywhere else in the region.

Overnight, the storm passed south of Puerto Rico, leaving about 7,000 people without power and more than 2,500 people without water. Gov. Alejandro Garcia Padilla ordered public employees in the U.S. territory to return to work on Wednesday.

The U.S. Coast Guard said all Puerto Rican ports had reopened except those on the southern and western coasts.